Fast starting fuel cell

Abstract

An electrical power supply system has a fuel cell module and a battery. The fuel cell can be selectively connected to the battery system through a diode. The system preferably also has a current sensor and a controller adapted to close a contactor in a by-pass circuit around the diode after sensing a current flowing from the fuel cell through the diode. The system may also have a resistor and a contactor in another by-pass circuit around the diode. In a start-up method, a first contactor is closed to connect the fuel cell in parallel with the battery through the diode and one or more reactant pumps for the fuel cell are turned on. A current sensor is monitored for a signal indicating current flow through the diode. After a current is indicated, a by-pass circuit is provided around the diode.

The invention claimed is: 
     
       1. A start-up method for a fuel cell module comprising steps of, a) connecting the fuel cell in parallel with a battery or other source of electrical power through a diode; b) connecting, by a controller, one or more reactant pumps to the battery or other source of electrical power at least before there is current flowing through the diode to power the one or more reactant pumps of the fuel cell module from the battery or other source of electrical power; c) sensing, by the controller, a current flowing through the diode; and, d) in response to sensing the current through the diode, connecting, by the controller, the fuel cell in parallel with the battery or source of electrical power through a by-pass circuit in parallel with the diode to by-pass the diode. 
     
     
       2. The method of  claim 1  wherein sensing, by the controller, the current flowing through the diode comprises monitoring a current sensor. 
     
     
       3. The method of  claim 1  comprising the steps of, closing, by the controller, a first contactor or other switch to connect the fuel cell in parallel with the battery or other source of electrical power through the diode; turning one or more reactant pumps for the fuel cell on; monitoring a current sensor for a signal indicating current flow through the diode; after a current is indicated, by-passing the diode. 
     
     
       4. The method of  claim 1  wherein the fuel cell is started in 5 seconds or less. 
     
     
       5. The method of  claim 1  further comprising performing one or more fuel cell module status checks or pre-start procedures before starting the fuel cell module. 
     
     
       6. The method of  claim 1  further comprising discharging the fuel cell module before starting the fuel cell module. 
     
     
       7. The method of  claim 1  further comprising a shut down procedure. 
     
     
       8. The method of  claim 1  wherein the fuel cell and battery or other source of electrical power are connectable to a load and optionally to a power grid.